[ospfd] Fix regression in SPF introduced by bug#330 fixes

[ospfd] Fix regression in SPF introduced by bug#330 fixes

2007-02-26 Paul Jakma <paul.jakma@sun.com>

	* ospf_spf.c: Fix regression introduced with bug #330 fix: The
	  cost update added to ospf_spf_add_parent only handled PtP
	  case, differing from same functionality in higher-level
	  ospf_spf_next. Regression diagnosed by Anders Pedersen,
	  mailnews+router-quagga-dev@news.cohaesio.com.
	  (ospf_vertex_new) Initialise vertices to max-cost.
	  (ospf_spf_init) Root vertex always creates with 0 cost.
	  (ospf_spf_add_parent) Remove the buggy V->W cost calculating
	  code, instead take the new distance as a parameter.
	  (ospf_nexthop_calculation) Take distance as parameter, so it
	  can be passed down to add_parent.
	  (ospf_spf_next) Dont initialise candiate vertex distance,
	  vertex_new does so already. Pass distance down to
	  nexthop_calculation (see above).